Femboy Frisk
by sinfulnature1123
Summary: Another drabble poll winner! A lust soul Frisk, male in gender but not in appearance, falls into the Underground. If you care much for story, you may feel free to keep on moving.
1. Chapter 1

Frisk woke in a bed of golden flowers. Sitting up, he was shocked to find that he had no bodily damage despite the massive fall he must have taken to have landed where he had. He'd not wanted to be back home anymore, he'd been shunned for how he was too many times, but he didn't want to be dead. He looked himself over as he stood up, finding no damage on his short skirt, or even his FBMs. He was still physically fine, and more to the point, still fabulous.

He shrugged, supposing it didn't matter so long as he was alright. He looked around the room he'd landed in, finding that there was a sort of hallway leading to another room. He stepped out of the flower patch and started down the hall, pausing slightly as he did. He could have sworn, just for a second, that there was someone else there. He'd been so sure that he wasn't alone, that there was someone or something else present.

He shrugged it off when he didn't see anyone else present though, deciding it must have been nothing. He headed down the hallway and into the new room. It was dark and empty save for a doorway to the rest of the cave, and another golden flower in the center of the room. It was different from the other flowers though, as it had a face. A bright, smiling, welcoming face, which helped to offset the oddity of it being there.

"Howdy," The flower greeted him as he approached, "I'm Flowey, Flowey the flower! What's a cute girl like you doing down here?" He asked. Frisk giggled at this, "Why, am I somewhere I shouldn't be? Can't be too bad if I got to meet you." He said, not corrected the flower. Flowey launched into his usual routine of explaining souls, the Underground, and LOVE.

Unlike the previous times he'd done this with the other humans though, the conversation had an air of flirtation to it. He wasn't sure what was compelling him to act this way towards her, other than her natural looks, until he saw her soul. It was red, but not the pure red of determination. It was a darker shade, between a scarlet and a cherry; the soul of lust. Flowey grinned as he decided to have a little fun with this timeline, his vines moving over and beginning to creep up her leg. "You know, there is another way I could help you improve the strength of your soul~" He said.

Frisk smiled down at him, "Gonna show me some 'love'~?" She joked, making him giggle cutely to keep up the act as his vines reached up under her skirt and to her panties. He had no intention of being gentle, as the thought of utterly destroying the girl with something lewd was an amusing one.

His vines reached her ass first, poking and prodding it as the other reached in for her pus… Flowey's eyes widened as he felt not a wet, warm hole with his second vine, but a stiff, twitching member. Flowey stared up at Frisk, but the human still appeared in every way female. He moved his vine down, checking if he was a futa, but no, he was fully male in spite of his feminine voice, appearance, demeanor and clothing.

Seeming to understand Flowey's confusion, Frisk said, "You can still call me 'she' if you want, I don't mind~" He purred, wiggling his feminine ass to get Flowey's vine to start teasing it again.

Flowey wasn't sure how to respond at first. Not gently, he knew that much. Dozens of vines rose up, wrapping around Frisk's legs and pulling him to the group, hiking up his skirt and holding his legs as far apart as possible, which was shockingly far, as the human was remarkably flexible.

"You need to be taught a lesson human, in this world, it's kill or be killed, take or be taken, or I suppose for you, rape or be raped!" Flowey laughed, but was surprised to find that Frisk was moaning from the painful way he was tied down, "Fuck yes Flowey~ teach me!"

Flowey, believing Frisk was just trying to play along so he could escape, dove four of his thicker vines hard into Frisk's ass. It was much, much tighter than he'd been expecting, and squeezed tightly around them as the human moaned, "Yes~!"

Flowey lashed at Frisk's ass with his free vines, but even this seemed to please him, making his member, now fully stiff, throb and twitch in excitement at the punishment. Flowey fucked the human's ass harder, forcing his vines in deeper and faster as he struck Frisk's ass harder, marking it grow red and marked.

Frisk tensed up, crying out as he came from the rough treatment. Flowey's vines stopped for a moment as he realized that the human truly did enjoy this. Before he could attempt to do anything about this though, Flowey fled to avoid a ball of fire thrown at him.

A tall, curvy anthro goat woman in an elegant purple dress walked over, "Do not worry my child," She said to Frisk, "I am Toriel, caretaker of the RUINS. I will keep you safe. I am sorry that horrid creature was doing such terrible things to do."

"Don't be, I deserved it." Frisk said, confusing Toriel. "What?" She questioned. Frisk nodded, "I was a bad girl Ms. Toriel," He lifted his legs, holding them skillfully behind his head, "I need to be punished~"

* * *

Frisk hadn't gotten Toriel to rape or dominate him yet, but he knew she wouldn't be able to resist for very long. She was so much more innocent than he'd expect for such a sexy monster woman. Frisk knew she had to have caught on to his flirting by the time she'd ask him to stay behind for a bit. Shed gone bright red when she asked him to practice stalling on a training dummy, and he'd responded by heatedly grinding on it.

He supposed he could wait for her. Every man and women he wanted eventually gave in, do unknowingly to his lust magic seeping from his soul and driving them wild. The only downside was that, on the surface, their opinions turned sour as soon as the lust wore off, and he'd be judged and abused for his actions, even when he'd not intentionally done nothing. But here in the Underground, Frisk figured he could try again as soon as he found another sexy monster.

Frisk didn't have to walk for long to find the first of them. It was a female, an anthro frog girl. She wore no clothing, showing off her lovely chest; which was oddly a darker tone than the rest of her body. Her legs were long and looked powerful, her expression was set as though she were on a mission, and her tongue, he was willing bet, would be pleasing long.

"Oh no!" Frisk exclaimed dramatically, "A sexy monster frog girl has trapped me! I'm doomed!" The frog girl didn't seem to pick up on his play acting, and seemed to believe his actions were legitimate. She wasn't the brightest of bulbs it seemed. Frisk smiled as he moved closer, "Perhaps there's some way I could convince her to let me go~?" He asked, hiking up his skirt.

The frog girl gasped when she saw that he had a cock, having been assuming from his appearance that he was female. Furthermore, his cock seemed to be locked in a cock ring, which would prevent him from cumming no matter how badly he needed to. He'd given Toriel the key, and though she didn't yet actually know what it was for, he hoped that she wouldn't untie him until he was a drooling mess at her feet, broken and loving her punishment.

The thought of the goat woman embracing her dominance and making Frisk her bitch nearly distracted him from his current mission, and he didn't have time to react as the frog girl forced him to the ground. He wouldn't have stopped her if he had been ready to, but he might have been able to better brace himself for the wall. The frog girl got on top of him and slammed her hips down hard enough to make sure that it hurt Frisk.

Frisk groaned happily at the pain. The frog girl moaned as she began riding his bound cock, loving how it twitched and throbbed inside of her. She let out her tongue; sure enough, long and slick. It moved over, wrapping around Frisk's hands tp prevent him from using them before looping back down and pushing into his mouth; either as a gag, a forced makeout to show who was in charge, or both. Frisk was hoping both. Not the best place she could have put her tongue, Frisk thought, but still very, very enjoyable for the sub boy.

* * *

Whimsun had taken a little more effort for Frisk's magic to turn dominant. The fairy girl seemed naturally submissive, and Frisk's flirtations only seemed to frighten her. He kept trying though, coming up to her gently and calmly sitting with her, talking to her as a friend, and letting his lustful magic work its charm. Whimsun gradually opened up more and more, his magic, as well as his being so kind, filling her with more confidence.

Things reached a head when he offered to share his monster candy with her. When Whimsun agreed, Frisk popped the candy into his mouth and pulled Whimsun on top of him, kissing her heatedly and passing the candy into her mouth with his tongue. She was bright red from the action as Frisk leaned in to whisper, "I want to apology for scaring you earlier, so how about I show you what else I can do with my tongue~?"

Whimsun was still nervous, and a little more gentle than he would have preferred, but Frisk knew that, with a little practice, she'd be a wonderful dom, and he was happy to help her get there.

* * *

Vegetoid's vines were a surprise. Frisk found the plant girl hiding and ready to attack him. She may have been after his soul, but his magic quickly turned her aggression into something much different, and her vines began undressing him before she even knew what she as doing, needing to stuff his girly ass and pump it full of her thick seed. Frisk pleaded with her to be gentle with him, knowing it would only egg her on.

She held Frisk against her while her vines lashed hard against his ass, reddening it with the force. When he was crying out and begging her to use his body, she pulled him against her body, two thick vines slamming hard into her ass, pumping into it roughly as another slapped against his already pent up cock. She wasn't going to let him go until he was too stuffed to walk properly. Frisk was going to need her fucking number.

* * *

Frisk got slightly frustrated with Moldsmol when he encountered her. The slime girl was laying on her back, looking up at the ceiling for no apparent reason, with no apparent goal in mind. She hardly even tried to attack him, simply swatting at him gently as though trying to get him to leave her alone.

Even when she was visibly aroused from his magic, and more importantly his sexy hip wiggling, she didn't make much of an effort to do anything. But Frisk was not one to give up, and so laid down next to her, letting his lustful aura get her more and more interested until finally she decided to go for it, climbing on top of the human and trapping his cock inside of her.

It was odd, as he was able to see his cock inside of her, even as he felt how tight it constricted around him. he shuddered in delight, knowing that if she were just a little more active, this monster could make an incredible dom.

* * *

Migosp and Loox were quite a surprise. The former seemed to be of a species comprised entirely of alt. genders, and he'd luckily stumbled upon a dick girl. The latter was on a species with rather interesting characteristics, such as his member splitting into two thick cocks instead of one. The two of them jumped out at Frisk, having evidently planned an ambush. Their desires turned from combat to pleasure the moment they saw him.

Frisk allowed the monsters to force him into his fours, the d-girl Migosp thrusting aggressively into his mouth to fuck his sexy throat while the Loox rubbed both tips against his girly asshole, thrusting both of them in roughly so he and Migosp could spit-roast the lustful soul. Frisk moaned in delight, bound member throbbing with want as he was railed. He was so tempted to ask if one of them could use their magic to unlock it, but no, he wanted to save his cum for the sexy goat woman.

* * *

Napstablook had been the hardest in the RUINS to handle, other than Toriel. But where Toriel was a tough nut to crack because of her resolve, Napstablook just had no drive to do anything other than lay on the floor. It was actually quite depressing to see the ghost boy just laying their, pretending to sleep in the hope that Frisk would leave them alone.

But Frisk didn't give up that easily. He laid himself on top of Napstablook, whispering to him, "No one should have to sleep without a nice war sleeve to put their member in~" He ground his soft bubble butt against the ghost's cock, half expecting the ghost to phase through him. But no, Napstablook didn't phase away, Frisk's charms keeping him solid, in more than once sense of the word.

When his member had gotten to full hardness, Frisk pushed his hips down, penetrating himself with the ghost's cock. He groaned softly, moving his hips until Napstablook's seven inches were completely hilted inside of his warm ass. Once he was balls deep, Frisk stopped moving, holding still as she held onto Napstablook, his lust magic pouring into him.

He only lasted a few minutes before needing more. His hips started moving slowly, pushing in and out of Frisk's ass slowly. She moaned exaggeratedly, urging him to keep going. He picked up the pace little by little, and soon Frisk was bouncing rapidly on top of the ghost, his cock hitting deeper and harder inside of him. Frisk squeaked in surprise and delight when Napstablook rolled over, pinning Frisk beneath him and beginning to thrust into him from above, his cock hitting his prostate hard, sending waves of pleasure through him.

Frisk moaned in delight, tongue starting to lull out. He thought the constantly pleasure and the build up in his balls might make him black out. As he neared unconsciousness, he could have sworn her heard something, a voice whispering something to him.

 _I wonder if I'll get a turn to.._


	2. Chapter 2

Frisk bit his lip as he laid on the bed in Toriel's house, gripping his small cock. It hadn't been removed from the C-ring yet, and stroking it only caused his balls to tighten further with the need to cum. He pictured Toriel playing with him, teasing him, refusing to finish him off. He wanted it, needed it badly. He'd been with her a few days, and his magic had brought her to the very edge of her limits.

He kept going, moaning out as he squeezed his throbbing, pent up rod. It was getting to be too much for him though. He got out of bed, letting his hard-on form a small, barely noticeable tent in his skirt as he left the room, going over to where Toriel was sitting in her chair. She looked up at Frisk, "Yes my child?" She asked of him kindly. She could tell from his expression and demeanor that something was wrong.

Frisk walked over to her, hugging her tightly. "Mommy, I-I need your help." He said, pulling himself close against her. Toriel hugged him back, "Of course my child, I can help you with anything you need." "Anything?" Frisk asked her, a note of desperation in his voice. "Yes my child." She assured him, looking him in the eyes to make sure he knew that she would help him.

Frisk smiled, knowing that between his magic and her need to help, she was right where he needed her to be to give in. Frisk moved even closer to Toriel, rubbing himself against her. "What are you doing my child?" Toriel questioned, unsure what he was doing. "Getting help from you~" He said, his voice taking on a tone of taunting. He lifting his skirt slightly, letting his throbbing, desperate cock rub against her soft dress.

"M-my child! Stop this at once!" Toriel said, aghast at what he was doing. "Make me~" He whispered, pushing her closer as he kept going, letting the bit of precum that managed to leak through smear across her clothes. Toriel pushed him off of her, "My child, this is wildly inappropriate!" She said, face burning bright red at Frisk's actions.

Frisk stuck out his lower lip, "But mommy, I need your help, look." he said, showing her his cock again. Her eyes widened at how swollen and in pain it looked, held back by the tight c-ring. She realized what the key he'd given her earlier was for, "Oh my child.. you must be in pain." She said, her desire to help momentarily overcoming her growing frustrations.

She took out the key and leaned down in front of him, unlocked him. Frisk grit his teeth as he held it in, knowing that if he blew right away, Toriel would know it had just been because it'd been held back, and wouldn't be mad enough to punish him. "Do you feel better now?" She asked, looking up at Frisk. Frisk grinned, grabbing her head and thrusting his hips forward and pushing his member into her mouth.

The hot, wet feeling was more than he could take, and his cum, pent up for several days now, all released at once, gagging Toriel as she was forced to gulp down his seed twice. Even when he pulled out, it continued to come out, his seed splattering over her face and shooting entirely over her dress, covering it in white seed and soaking through it.

Toriel looked at Frisk, and in her eyes, he could see the last straw had broken. She stood up, grabbing Frisk's wrist tightly and pulling him into her room. She knew she was giving him what he wanted, but she didn't care. His magic and his actions had her too frustrated in too many ways. She pulled off her ruined dress, letting Frisk see her lovely white fur and sexy body as she sat down on the bed, pulling him onto the bed and bending him over her lap.

Frisk moaned as Toriel's hand came down hard on his soft round ass, her fire magic making her hand painfully hot as it struck him, leaving a bright red mark as his ass bounced with the strike. "You have been a terribly bad girl my child," Toriel said, having finally given in to the temptation and decided to take Frisk for the bitch he was, "You need to be punished or you will never learn."

"Yes~" Frisk moaned, his hard, tiny cock rubbing against her soft warm fur from how he was bent over her, "Punish me mommy~" This earned him another blissful smack to his sensitive ass, "Wanting to be punished.. by one you call mother no less," Toriel shook her head, "You may very well be too lewd for normal punishment to fix." She said as she struck his ass again, making it even redder.

Her hand lingered on his ass, fingers trailing over the temptingly soft skin and pausing between his cheeks, "Perhaps.. more drastic punishment is needed.." She said. Her hesitation was overridden by the lust magic Frisk's pink soul let off, and she forced two fingers into his extremely tight, greedy hole. She bite her lip as she felt how tightly he gripped her fingers, as though not wanting them to pull out of him. Toriel could only imagine what she would do to this human if she were a male. He likely wouldn't walk straight for a week.

He still might not she thought as her fingers pumped mercilessly into him, a third and fourth being added well before he could have gotten used to the fourth. The sounds of his pained whimpers nearly made her stop as she realized she was hurting him, 'no,' she thought, Frisk's magic urging her on, 'punishments should hurt, he needs this, it is the only way.' Her magic filled her fingers, heating up inside of Frisk's ass as she forced them knuckle deep into him, then pushed even deeper to see how much would fit inside.

She only stopped when she felt him suddenly become too tight for her to go any deeper, his tiny femboy cock shooting cum onto her legs as he reached the peak of his pleasure. "You are a filthy child," Toriel said, "Dirty, lewd minded.." She pulled her fingers out of him, grabbing the toy he had brought her on the second day he'd been with her. She hadn't thought she would actually use it, but now she couldn't imagine not using it.

She put the toy on, lining its tip up to Frisk's ass as she bent him over her bed, "N-no mommy, don't use that on me," Frisk begged, "It'll hurt to much~" He said, his words only increasing the magic's effect on Toriel. She smacked his ass again, causing him to yelp in blissful pain at the strength she put behind it before she jerked her hips forward, penetrating him with the strap-on.

He cried out, his ass gripping the shaft, practically begging for more. "You will learn to be a proper girl my child," Toriel grunted as he pumped the toy into his girly ass hard, "If I have to punish you every single day, I will teach you to act proper." "Yes mommy~" Frisk moaned, "Punish me for being bad!" He was loving how good she was at this, and was going to enjoy staying with her; but he wasn't so sure about staying with her forever. There was an entire underground of monsters to rape him after all.


	3. Chapter 3

**Apologies to anyone who feels that I'm speeding through this a bit too fast. My philosophy with this story is that everyone already knows the details of the game, so there's no point going into too much detail about things we already know, hence my putting more focus on things I've added, such as the less than normal gender attributes of certain monsters.**

* * *

Frisk was more than a little upset at Flowey now. When he'd woken up after a long night with Toriel and found him in a hallway in the RUINS, she naturally followed him, wanting his sexy vines. But the rude fuck didn't even attempt to rape him, and instead led him out of the RUINS and into Snowdin forest.

The door to the RUINS locked behind him, making it impossible for him to get back inside to Toriel. With nothing else to do, he simply pressed on. It wasn't a complete loss, as he quickly met the rather alluring royal guards in training that reportedly guarded Snowdin forest, the brothers of Sans and Papyrus.

Frisk had, at first, assumed he was looking at skeletons when he saw them, but despite the pure whiteness of their bodies, they weren't all bone, closer to revenants than skeletons. This was promising, since it meant they probably weren't missing the only bones that counted.

Currently Frisk was on his way through the forest and towards Snowdin Town, his path blocked by an icy blue feathered harpy-like man called Snowdrake. Frisk figured out quickly that the poor guy was just looking for someone to laugh at his jokes, and the cute girl made of ice standing next to him was just looking for some attention. Dealing with them was easy.

Frisk's charm got Snowdrake to believe he was funny, and a sexy pose melted the overly elaborate hate right off of the Icecap girl's head. She was shocked at first, then flattered when Frisk let her know she was even better looking without it. With their spirits high, and Frisk's lust magic flowing through them, they decided to celebrate with a quick fuck. They had no hostility towards Frisk, but his natural submissiveness led to them still wanting to top him,.

Frisk hadn't expected fucking in the snow to feel so good, the chill against his bare skin as he was dominated feeling wonderful. Icy rode his face, grinding her wet pussy against his cute face while Snowdrake held onto his hips, thrusting into the bitch boy's ass. The fun was so heated, Frisk swore he saw steam rising from their bodies.

After finishing up with them, saving both of their numbers for later, Frisk continued on his way, and was rather excitingly pounced by two dog men. The anthro dogs seemed to be the most vulnerable to Frisk's lust magic in the underground so far, possible their strong connection to instinct.

Frisk had barely said anything before Lesser Dog and Doggo had him on his fours, pounding into his mouth and ass and letting him know he was their little girly bitch. Frisk had never taken a knot before, and the new experience of the canine cock swelling inside of him was almost enough to burn out the lust soul's endurance.

Thankfully, having sex only fed into his magic, making it almost impossible for him to run out of sexual stamina. He was still just as raring to go when Dogamy and Dogaressa appeared, following their noses to Frisk, who reeked of cum and lust magic. the happy couple decided to punish Frisk together for being such a slut puppy.

Dogaressa bent Frisk over, smacking his little ass hard while Dogamy showed him the only thing a slutty puppy's mouth was good for. Frisk moaned around Dogamy's cock, sucking it hard as his throat was fucked, and wiggling his hips for more smacks to his sexy ass.

When Dogaressa felt his hard-on against her fur, and her husband had pumped his throat full, she dropped him onto his back, grinding her foot painfully against his cock as a punishment. Frisk moaned in a pleasured pain, letting himself cum against her foot.

He received another smack for this before Dogaressa ground her cum covered foot against his face, making him lick it clean, then making him lick both of them clean together, enjoying the taste and smell of her feet while Dogamy took his turn punishing the puppy's ass.

Frisk was still walking funny when the last of the dog guardians found him. He had seemed small at first, but Frisk's eyes widened in shock and excitement when he saw the nearly eight foot dog man known as Greater Dog looking down at him.

Greater dog was just as easily affected by Frisk's lust magic as the others, if slightly too affectionate to be actively aggressive with him. Thankfully, Greater's sheer size made him rougher with Frisk just by default the moment he had the human on his back with his tree trunk of a cock abusing his ass like it was his personal fuck toy to break.

He groaned as Frisk's asshole stretched to accommodate his size, Frisk's eyes practically rolling back in his head from the pleasure. When Greater began to knot, frisk felt he might once again begin to black out, and would have frozen to death if not for the massive fluffy animal laying on him, and the nice, warm seed filling him up like a balloon.

Frisk hadn't thought it would be possible for him to like Snowdin, or anywhere, as much as he had the RUINS, but here he was, proven thoroughly wrong. And the fun he'd had in the forest only made him twice as excited to get to the town. He was sure he could get the sentry brothers to take him home for a night or three, and even if he couldn't the town was bound to be filled with other monsters willing to take him.


	4. Chapter 4

Frisk bent over the Shopkeeper bunny's desk, letting her hike his skirt up. Frisk had gotten side tracked so many times with the various sexy guardsmonsters that he was almost surprised when he did finally make it to Snowdin town. When he had reached the town, he'd found that he'd been right about it being just as full of monsters as the forest. In fact, it seemed to have even more. His first stop had been the shop, and after buying some food, he'd decided to have a little fun with the rabbit woman running the shop, his eyes drifting over her form as he'd let his words, magic, and looks work their charms.

"Dirty slut," She practically growled as she smacked his feminine ass hard, "Probably planning on just loitering in here with that slutty skirt of yours pulled up weren't ya? Letting anyone who walked in fuck you silly like a whore in a brothel." "Fuck yes~" Frisk moaned, both from the smack and from the idea, earning another strike to his ass as he did so.

"I'll show you what we do to whores here in Snowdin." She said, leaving the room the room and returning quickly. When she came back, her pants and underwear had been left behind, letting her white furred hips be on display. More importantly, she'd retrieved a toy from the other room, a thick strap-on cock. She noticeably didn't lubricate it before moving behind Frisk, forcibly bending him over the desk again and lining the toy up to his boy-pussy.

"You want it bitch?" She asked, rubbing the tip of the toy member against his puckered hole. "Yes mistress~" Frisk purred to her, grunting as she jerked her hips forward, penetrating him hard with the toy. She had to move her hips hard in order to get the toy into him without lubing it up first, and the effort only made the fucking that much rougher, and that much better, for the horny little lust soul taking it.

The shopkeeper wasn't the only bunny girl Frisk had fun with in Snowdin Town. He'd found another outside, a cute, thinner bunny in a knit sweater. By herself, she was already adorable, but she was pushed well into the sexy category by the rabbit boy she had on a leash. He looked only a year or so younger than her, and was on his fours in front of her with her leash connected to his collar. He wore nothing else, and had his tight little rump stuffed with a plug.

Frisk sauntered over to them, letting them know he was willing to help her train her little pet if she wanted. "I'm in need of a little training myself though~" He added with a wink before walking over to the inn, glancing over his shoulder as he went through the door to confirm that the bunnies were following him. The rabbit girl running the inn let him have a room for free, claiming it was because he looked so cold and helpless, though Frisk was pretty sure he'd be paying for his room one way or another before he left it.

He went upstairs to his room, undressing himself. The rabbits came into the room to find that he'd removed all but his high heeled shoes, and was currently waiting on the bed for them. The sub-bunny, evidently named Cinnamon, was instructed to give Frisk a kiss before bending over the bed with him. Even as submissive as Cinnamon clearly was, Frisk still ended up on the submissive end in the kiss with him.

Once they'd both bend over the bed, the dom bunny walked over, bringing her paddle-which Frisk was decently sure she'd been hiding in her shirt-and beginning to strike both of their asses with it, one after the other. She didn't sound very aggressive as she reddened their asses, actually seeming quite cheerful as she punished them. It was almost amusing, though Frisk was more focused on the pleasing sting of her toy against his ass.

When she'd finished with that, she ordered Cinnamon to lube up Frisk's cute little hole with his tongue. He obeyed without question, spreading Frisk's round cheeks with his hands and burying his tongue inside. Frisk moaned against the bed as he felt the bunny boy's tongue scrap against his walls, moistening and probing deeper into him. Frisk supposed he shouldn't have been surprised by how skilled the sub bunny was with his mouth.

Cinnamon moaned against Frisk's ass as his own was groped by his dom. She began moving the plug inside of his ass, grinding it deeper, and pulling it out before shoving it back in until his hips were moving her with hand. She couldn't get enough of playing with Cinnamon's cute little ass. Frisk's may have been even girlier, but she she loved Cinnamon to much to ever fuck anyone's bus his.

It seemed that the shop keeper rabbit wasn't the only one with toy cock for punishing girly boys. The dom bunny's was much larger than the shop keepers though, eight inches long and four thick. She removed Cinnamon's plug and replaced it with the toy, Frisk impressed by how little resistance the bitch bunny's ass gave to the toy, and how much resistance it gave when the toy tried moving back out of him.

Cinnamon's dom moved him back up, positioning his body so his cock was lined up to Frisk's ass. She let her thrusts into Cinnamon push Cinnamon's cock into Frisk, all three of them moaning happily as Cinnamon's dom pounded him hard, using his cock to pound Frisk just as roughly. They were just reaching the end of their first round together when the innkeeper's head poked through the room, evidently wanting to collect Frisk's payment for the room. She blushed deeply at the sight, only to grin eagerly when she was beckoned into the room to join them.


	5. Chapter 5

Frisk's battle with Papyrus had gone more or less the same way as his fights with all of the monsters up to now. Lots of flirting and sexy poses, mixed in with an aura of lust until the offending monster was too horny to fight. Unlike the others monsters though, Papyrus didn't just throw him onto the snow and fuck him, instead offering him a date before returning to his house with the human.

Frisk wasn't sure if he was confused or impressed by Papyrus' resistance to his own lust, but he was grinning ear to ear when he walked into Sans and Papyrus' house. Not that he hadn't found the cage they'd been putting him in inky, it just wasn't as exciting as actually being invited in by the sexy skele-revanents. They'd promised not to call the head of the royal guard, Undyne, oh him.

Frisk was excited to meet her, sure, especially if she was as naturally aggressive as Papyrus was making her sound, but Frisk would meet her in due time. right now, it was the brother's turn with him, even if they didn't fully understand what that turn was exactly.

He hung out with the brothers for a few minutes, enjoying their company. Soon though, he reminded Papyrus about the date that he'd been promised. Papyrus gasped in alarm at the reminder, "You're right human, how could I forget!? Where should we go?" He asked. Frisk smiled, "Well, since you're so great and all, it doesn't really matter where we go so long as you're there. How about we just go up to your room~?"

Papyrus didn't seem to notice Frisk's suggestive tone, or perhaps he just couldn't recognize lust even when a massive dose of it was flowing through him from Frisk's soul. Sans did and his eyes noticeably followed Frisk's ass as he went up the stairs, stopping at Papyrus' door to wink back at him before going inside.

Papyrus showed Frisk around his room, which Frisk couldn't help but find slightly adorable. But he needed to re-assert who the cute one in the room was, and though sat on the bed, beckoning Papyrus over. "It doesn't seem like you know very much about what humans do on dates," Frisk said, "So I'll show you~"

"Really? Wow, thank you hum-" Papyrus' words were cut off by him being pulled into a kiss. Papyrus did seem to recognize this though, and immediately blushed a deep blue. He didn't stop Frisk though, as this was a date and it would be rude tio do so.

Frisk took Papyrus' hands, moving them along his own soft legs, up his skirt, and placing them on his l;little ass, instructing him to grab, squeeze, and rub it for him. Papyrus did so, and the action seemed to wake other parts of Papyrus' body, Frisk licking his lips as he saw the tent slowly forming in the monster's shorts.

At Frisk's instruction, Papyrus began removing the clothes separating Frisk from the monster's member. When Papyrus had undressed and turned back to the bed, he found Frisk sitting on it naked, completely on display aside from his heels.

His already stiff member hardened further, and he walked to the bed as Frisk beckoned him over. Frisk gripped Papyrus's length, beginning to stroke it gently before moving his head down and kissing its tip. Papyrus moaned softly, and Frisk began to drag his tongue along his cock, licking along his length gently before sucking at the tip of it.

He paused when he heard a sound at the door. Looking over, he grinned when he realized Sans hadn't been able to resist peaking in. He gestured with his fingers for Sans to come in, and after a moment of hesitation, the door opened and Sans walked in, white face blushing as blue as Papyrus' . "The more the merrier~" Frisk purred with a grin.

When Sans was by the bed as well, Frisk moved his other hand to the other monster boy's crotch, grubbing it gently before pulling his short and underwear down. He was actually a bit surprised by the size of Sans' cock, not having expected it to be as big as Papyrus', let alone as much bigger and thicker as it was.

Frisk smiled at this, beginning to stroke both of the brothers, his skilled hands having both of them moaning and leaking pre-cum in only moments. He used the pre as lube to stroke them even faster, and kept going until he felt them both getting close.

When he did, he moved himself lower and aimed both of their rods at his face, opening his mouth with a smile as he started to jerk them both faster. It may have been his new positioning that sent the brothers over the edge more than his stroking, and soon both were groaning in pleasure as they came, painting Frisk's cute face with white-thought slightly blue tinted-cum.

Licking his lips of the thick, tasty seed, Frisk crawled up onto the bed, getting on his fours for the brothers to share him. Since it was technically Papyrus' date, it was he who got behind Frisk, his member lining up to the human's ass while Sans moved in front of him, his fat member placed in front of Frisk's face.

Frisk rubbed his face against it affectionately, loving how it felt. He opened his mouth and took the first inch or so inside, sucking on it as he grubbed his cheeks back against Papyrus' member to let him know he could start. Papyrus, acting more on instinct than on actual knowledge, took hold of Frisk's hips and moved his own forward, pushing his solid cock inside of the the bitch boys tight hole.

Frisk prided himself on still being so tight despite his many thick pricked encounters. A virtue of his lust magic he supposed, or perhaps he was just naturally always fuckable. regardless, he didn't think it was going to change anytime soon, even when he inevitably had both brothers pounding him at once.

* * *

 **Yes, that's right, I said blue. Nowhere in Undertale is Papyrus associated with orange, I'll never get why so many fan-things have him with orange when not only does it never happen, but even Sans has more of a connection to it, as his blue eye occasionally flashes other colors than blue.**


	6. Chapter 6

Frisk ended up spending a few straight days with Sans and Papyrus, only actually leaving the bedroom once or twice the entire time. Soon though, he knew he needed to move on, and when he told them so, the brothers didn't stop him; so long as he promised to visit whenever he had the chance.

Frisk happily agreed, giving them both a goodbye kiss, then headed towards Waterfall. He wouldn't have to wait long for his first monster encounter there. he'd barely made it halfway through the first cave before two appeared in front of him.

Frisk smiled flirtatiously when Washua and Aaron appeared together. The former was a short, but barrel chested monster. His body appeared to be almost jar-like, likely filled with water and perhaps soap if his dome-like head was any indication.

The latter resembled an anthro fish, like a merman who's fish tail had separated into finny, scaled legs. His body was practically rippling with muscle even without him moving. They were odd creatures to be sure, but Frisk was able to find them as sexy as any of the other monsters he'd encountered thrust far, and immediately commenced flirting with them while his lust soul drew their attention.

Aaron was fairly easy to get hot and bothered. The moment his attention was no longer on his own muscles, he quickly grew rock hard from Frisk's girlish form. Washua was a bit trickier though, having his attention so immediately locked on cleanliness that even when he was visibly sexually aroused, he still couldn't take any action not related to cleaning.

Frisk eventually figured out a way around this though, convincing the little cleaner monster that he was utterly filthy inside, and needed him to clean him out. Washua didn't need to be told twice, immediately pinning Frisk on his back ans savaging his asshole with his cock.

Frisk groaned in delight from the roughness, shrieking in pleasure when Washua flooded his insides with warm water/cum(?) to clean him out. The sensation was intense, and frisk was given no time to recover from it, as immediately after he was cleaned out, Aaron took his own turn, hilting his thick, muscular member inside of Frisk's ass to pump it full of his own seed. This would only cause Washua to need to clean it again, and a sexy, if rather vicious, cycle would form.

When the cycle was finally broken by the two monsters essentially collapsing in exhaustion, Frisk got up and walked on. In a later section of Waterfall, Frisk found himself faced with a more feminine monster. She still resembled Aaron, but only in the sense of looking like a mermaid with legs instead of a tail.

Frisk quickly learned that her name was Shyren, and she lived up to her name; doing everything she could to recluse her way away from even the other monsters. Frisk had to change his tactics, as being aggressively submissive (and isn't that an odd phrase) only seemed to frighten her off.

Instead, he approached gently, and slowly, deciding to follow her tune and let things move with her rather than him. This proved to be much more effective, and before he knew it, their song, in both a literal and metaphorical sense, was a heated, intense display for all to see, Shyren having loosened up enough for Frisk's magic to re-ignite her lust.

She didn't even seem to notice the crown forming around them, half there to listen to their duet, the other half there to watch Shyren riding the femboy with no reservations about being watched.

In a cave following that one, Frisk approached what he assumed to be a Moldsmol. He was excited to see what the slime monster would be like in this part of the underground. He was wrong on two fronts. The first was his assumption that it was a Moldsmol, and his second was assuming it would be anywhere near as passive as the Moldsmol girl he'd meat in the RUINS.

The moment he approached the Moldsmol, it was revealed to actually be a Moldbygg. It tripled in size, pinning Frisk beneath his weight as his thick member rammed into Frisk's girly ass with no warning or mercy. frisk moaned, unable to even pretend he was upset with the result as the Moldbygg plowed him into the ground for several minutes, pumping him so full of thick, slimy seed that he looked almost pregnant by the end.

Shortly after that, Frisk was encountered by something he had not been expecting in the least: A dummy. The dummy referred to himself as Mad Dummy, and floated off the ground, "My cousin was a ghost who lived inside of a dummy just like me, and he was this close to fully bonding with his dummy until YOU came along! Your shameful display on his dummy form embarrassed him right out of his body!"

Frisk gasped at this, having had no idea, "I'm so sorry, I'd make it up to him if I could." "Don't apologize to me, apologize to him!" Mad Dummy pointed to the second ghost. He looked a bit like Napstablook, but shorter, and with a somehow even more listless expression, evidently currently known as Sad Dummy, despite not even having a dummy body.

Frisk frowned at this, deeply sorry for his actions. He couldn't do anything to fix his host, but there was one thing he could do: apologize the only way he knew how. Sad dummy was reluctant to accept it, but figured it couldn't hurt anything now. frisk dropped to his knees, engulfing Sad Dummy's member.

He put all of his passionate into making it as pleasurable as he could to make up for what he'd done, and it only got better when Mad Dummy evidently felt that punishment was required as well as apology, and showed him how hard his Dummy form's member could be from behind.

Frisk spent more than an hour with the two dummies, and when he was done, Sad Dummy was more used to sexual things, and as a result, was once again able to bond with the dummy he'd been embarrassed out of. Satisfied with this, Frisk moved on through Waterfall.

And yet, strange though it might seem, Frisk's next Waterfall encounter was even stranger than that. He was walking through one of the darker sections of the cave when, out of nowhere, a female monster appeared. She looked a bit like an anthro cat, with white fur and black hair. She had wings though, and wore nothing but a thin blue sweater. She smiled at Frisk, then gasped as though suddenly seeing him, "Hu-man!"

Her arm stretched out bizarrely far, Grabbing Frisk and reeling him in. She locked her legs around him like ropes, spearing herself on his cock as he was bound to the ground., She moaned as she rode him roughly, "Tem fuk hu-man, then tem tak back to Tem Villag, so oder Tem may Rap hu-man for al nites!"

* * *

 **1\. Yes he was encountering Undyne between the monster hook ups, but they hardly lasted long enough for his magic to work, so they weren't worth mentioning, the same will apply for Mettaton in Hotland. 2. Who else thinks that it's weird that we never actually canonically meet the ghost we scared out of the RUINS dummy?**


	7. Chapter 7

Frisk had seen the armless orange monster who was evidently literally named Monster Kid back in Snowdin, but hadn't taken much note of him. He'd flirted with Kid a few times when he saw him in Waterfall, they'd both traveled through the place together, meeting up occasionally as he looked for Undyne while Frisk tried to avoid her.

But in this most recent encounter, Kid had finally realized that Frisk was a human, and rather than side with Undyne on the matter, he'd stood up to her, and action that drove her off, buying Frisk a little more time. Frisk felt that he owed Kid some kind of reward, and while Kid refused it, Frisk refused to take no for an answer on this matter, and eventually Kid conceded.

Frisk got down on his knees in front of Kid, smiling up at the armless monster as he moved his lips close to his crotch, giving his member a gently kiss. Kid groaned, his already semi-stiff rod growing fully erect. He wasn't huge or anything, Frisk wasn't going to make him feel bad about that; he wanted to reward the guy, not tease him.

He moved his hands to hold onto Kid's hips, taking his member into his mouth and beginning to suck on his gently as his tongue moved slowly around the shaft. "Y-yo.. this is s-so wrong man.." He moaned, though he made no attempt to stop Frisk, and frisk was well aware that the monster had sneaked a peek up his skirt when he'd given him a lift up onto the ledge earlier.

Frisk bobbed his head slowly along Monster kid's cock, sucking on it a little harder. He had to force himself to not go all out, wanting to let Monster Kid saver what was probably his first time with anyone. Kid moaned in pleasure, finding it hard not to cum right away from the feeling of frisk's wet, soft, warm mouth wrapped around his cock.

Somehow he managed to last a few whole minutes without bursting. Frisk gulped down his seed like a pro when it came, looking up at him with a smile. Frisk's lust magic was able to keep Kid hard after his climax despite the monster's utter lack of experience.

At Frisk's request, Kid laid down on his back, his member sticking up in the air., Frisk crawled into Kid's lap, straddling and then mounting the monster';s member, moaning as he lowered his little ass onto it and began to ride him.

Kid groaned at the feeling, Frisk's cock even feeling tight around Kid's smaller member. Frisk moved his hands down to hold onto Monster Kid's b as he bounced on his cock, going a little more fast paced this time, wanting to give him something intense as a reward.

Kid groaned in amazement at the feeling, instinctively thrusting up into frisk to force his cock deeper into the warm, tight hole squeezing his rod. Frisk moaned encouragement to him, bouncing harder on Kid's cock. It didn't take long for Frisk to take him balls deep inside of his ass, clenching tight around him.

This was more than Kid could handle, and he reached his limit shortly after, groaning as he came hard into Frisk's rear. Frisk shuddered happily at the feeling, staying on Kid's cock until his climax had settled. He leaned down, giving Kid a quick, affectionate kiss before getting up off of him and heading forward to face Undyne.

Undyne had been waiting for Frisk right outside the entrance to Hotland to intercept him. She was still confused by Monster Kid had been willing to help him, but evidently wasn't letting herself get bogged down thinking about it.

She was still Captain of the Royal Guard, and he was still a human who needed to be dealt with. When she jumped down to face him, her green magic bound him into place, making it impossible for him to move from the spot with her moving him.

Undyne knocked Frisk onto the ground, a small section of her armor removing from her crotch to reveal her pussy. It seemed that Undyne had heard tale of how Frisk had gotten through the underground so far, and believed that if sex was his weapon, sex was the only way to break him.

Frisk couldn't help but laugh at this, as she wasn't altogether wrong in this belief. Undyne took his laughter as a challenge and dropped herself hard onto frisk's tiny cock, the force of her muscled and the weight of her armor making it a painful, intense ride.

Frisk groaned in pain, purposefully trying to hold out longer so it wouldn't stop. Undyne aggressive ground her hips against him, as though trying to fuck him into the dirt., She slapped him across the face, and even spit on him as she rode.

This was what made it too difficult for Frisk to hold out. His member erupted inside of her pussy, pumping seed into it. Undyne evidently hadn't actually been prepared for this, making frisk what exactly she had been prepared for, and her green magic wore off.

With a grin, frisk got an idea, crawling out from under her and bolting towards Hotland. By the time Undyne caught up with her, he was right at the edge of the volcanic terrain. His utter lack of clothing made the heat easy to handle, but Undyne was practically being cooked by her armor, leaving her with only one option: remove it.

Undyne practically forced her armor off of her body with sheer force of will. Undyne's chest was completely flat, but she was sexy for other reasons. For one, it was clear her strength wasn't just magical, her body well muscled, but not so muscled that it became unsettling.

But that wasn't what had frisk drooling. No, that was the futa cock the fish girl had evidently been hiding in her armor, her true, final spear. It seemed apparent to Undyne now that she would have no choice but to use it. She grabbed frisk's head, forcing it down onto her cock.

She wheezed out in shock at how good his mouth felt around her cock as he began to suck her, practically milking her cock. She thrust forward, hips pumping hard as she fucked his throat aggressively. Between the hot air and the thick cock, Frisk was finding it hard to breath; which only made the experience more intense for him.

When Undyne came, Frisk almost wasn't able to take it all, but managed to get every drop just before Undyne looked down at him. The heat, both literal and sexual, was more than Undyne could handle. She picked Frisk up, carrying him back to Waterfall. "We.. we're going.. to my place.. we can.. finish this there.."

Frisk agreed wholeheartedly, certain that, by the time they were done, Undyne would be just as on his side as Sans and Papyrus.


	8. Chapter 8

Frisk had ended up spending a few straight days with Undyne. The first was just Undyne using and abusing Frisk's body in every way she could think, which Frisk later realized was due mostly to her being extremely pent up, not to mention frustrated about a crush on another monster he'd yet to meet.

On the second day he'd been with Undyne, two things had changed in their dynamic. She'd grown to no longer dislike him, raping him out of affection now, rather than hatred. Frisk had taken the time to explain his situation to her during one of her recovery periods in between fuckings, and actually managed to get her on his side.

The second was the house burning t the ground, as they'd been too busy with sex to notice how high the oven was getting. As a result, the remaining days he'd spent with Undyne had also been spent with Sans and Papyrus, as the royal guard fish girl had elected to stay with them for the time being, and the four of them had a lot of fun together before Frisk, utilizing a mysterious river boat, returned to Hotland, this time actually making it inside.

He was first faced with Alphys, an orange, lab coat wearing monster girl resembling an anthro lizard. she was dressed in a lab coat that did little to hide her rather round form. Frisk didn't mind, finding her cute in her own way, though her intensely repressed attitude made it too hard for his magic to lure her into sex; especially with the stress of the killer robot she'd accidentally set loose looming overhead.

Said robot was named Mettaton, and was unfortunately also immune to the lust magic by virtue of being a fucking machine, which Frisk found very unfair. He was only around long enough to be a bit of a nuisance, tricking Alphys into revealing her crush on Undyne on live television.

Thankfully, Frisk learned, Sans has had helpfully distracted Undyne herself away from the television to prevent Alphys getting too embarrassed. With Mettaton threatening to be a pest throughout the rest of the trip, Frisk got ready to keep going through the underground.

The first monster Frisk met in Hotland other than Alyphs and Mettaton was Vulkin. She was a short, cute little monster. Her skin was like orange hot rock, her face blissfully ignorant and her hair a mini-flow of magic lava.

Luring her into some fun was easy, as she was remarkably gullible. She seemed to believe her lava was a healing item, so it didn't take much effort to convince her that her pussy would heal him to.

Once she believed that, she pinned Frisk down with magically cooling lava, essentially shackling him to the ground with the rock as she straddled him, grinding her hot pussy against his cock before taking it inside.

Frisk wasn't sure what made it better, the weight of the Vulkin's molten body dropping painfully onto him, or the intense, unrelenting heat that was practically cooking his cock as she rode him into the ground.

Thankfully her molten shackles vanished when she came, the heat having milking two orgasms out of the femboy. He gave Vulkin a little kiss before moving on through Hotland. It wasn't long before he was met with another bizarre but sexy monster girl.

She was known as Tsunderplane, and looked a bit like a robotic woman, metallic humanoid form with a face like a front of a plane and plane wings sprouting from her back. Despite her obvious attraction to Frisk, she was surprisingly difficult to get on top of him.

She seemed recoil whenever he got close to her, and his lust magic only seemed to keep her away. Eventually Frisk managed to catch on to her vibe, dialing back his lust magic and proclaiming that he didn't even want her to dominate him anyway, and that she probably wouldn't even do it right anyway.

With such a challenge on the table, Tsunderplane ran towards Frisk, pinning him to the floor to prove him wrong. She dropped her metal body onto his cock, getting off more on his pain than her own pleasure as her legs locked beneath him. It was nearly two straight hours before Tsunderplane was too worn out to continue. Frisk made a mental note not to underestimate her kind of monster again, and kept going.

Frisk was next faced with his first male encounter in Hotland in the form of Pyrope. His body appeared to be weaved out of red coiled ropes, his head, hands, and feet all made of orange flames. He had a wide smile on his face, and his attacks were easy once Frisk realized his magic could be walked through.

He was the easiest in Hotland to lure into sex, as he was halfway there already, and just had to let him know that if he wanted to warm up, Frisk had a hot ass for him to take. Pyrope's grin widened, and his ropes extended, typing Frisk in tight, skin burning bondage as he reeled the girly boy in, sinking his red hot-literally-cock into Frisk's tight ass.

Groaning as he found that Frisk hadn't been kidding about the heat; nor had Frisk. The monster's member was made of the same orange magic flames as his hands, feet, and face, and since Frisk couldn't move due to the bondage, which even had his tiny cock tied up, he was helpless against it as he was fucked brutally against the ground, Pyrope's flaming cock filling his bowels with burning hot seed.

When he was done, and the feeling returned to Frisk's body, the femboy got back to his feet and continued on his way through Hotlands, happy to report that it was just as HOT as the rest of the underground, a pun which he was sure would earn him a little affection from Sans if no one else.


	9. Chapter 9

The final battle in Hotlands proper came from the Royal Guards. Evidently the guards o1 and o2 hadn't gotten the memo from Undyne that Frisk was no longer a target, and the two guards, respectively an anthro bunny man and a draconic, both armored, both buff and wielding blades, ame at Frisk to take his soul.

Frisk had a relatively easy time with them, as he could recognize an unrequited crush when he saw it, and knew after just a few turns how hard 01 was getting for 02 as the heat of the battle forced the draconic guard to remove his armor.

In an attempt to push 01 to the edge of his restraint, Frisk sauntered sexily over to 02, beginning to grind himself against 02, the heat causing the guard to remove the rest of his armor, his fat scaly member being freed as well and rubbing against frisk's ass.

And that was more than 01 could handle he pushed Frisk back away from 02, stripping his own armor off before the heat gave him a stroke. He declared his love for 02, who unsurprisingly accepted, having had the same feelings, despite being better at hiding them. Frisk grinned, offering to be their first date.

He guards, full of lust for Frisk's magic and affection from each other, happily agreed. Frisk laid back on the ground, 01 and 02 lining up their members, both fully stiff from the heat of the moment now, and thick as logs to Frisk's delight, to Frisk's ass and mouth respectively, both thrusting in hard and beginning to use the human as a fuck toy, both grunting with the effort of burying their rods deeper inside of him as though wanting to meet him in the middle.

If it were ever possible, he was pretty sure they would have been able to do it, though they came right when they were both balls deep into him, flooding Frisk on both ends with their seed. O2 pulled out, picking Frisk up to join 01 inside of his other hole. Frisk cried out as he was stretched out by the lengths hammering at his hole together, turning their heads to kiss each other as they pumped into him aggressively.

It was some time before the guards finished up with him, heading to continue their date with Nice Cream afterwards. Frisk got up, as soon as his legs were no longer numb, and continued through Hotland.

His last battle in the area wasn't so much in Hotland as it was in the section leading out of it, a long dark hallway full of spider webs. He didn't mind really, remembering the spiders in the RUINS.

Their pastries had tasted great, and given him the energy to keep fucking, as his magic had only just been kicking in back then. So naturally, he was overjoyed when he saw Muffett. The tall humanoid spider woman looked amazing standing on her web of purple.

He frowned slightly at her assuming that he'd been stingy with his money, but when he heard that the greedy were to be punished, he played dumb and claimed to have not spent a scent on helping the spiders. Frisk was pulled into her web, trapped in it by the purple magic.

"You'll have to work off your debt." Muffet told him as she bent him over her knee, spanking him hard with two hands at once while a third covered his mouth. Frisk moaned in delight against Muffet's fingers as she reddened his already sore ass, his lust magic seeping into her, and turned a punishment into a pleasure as Muffet began getting wet from abusing the boy, wanting to do more to him, wanting to hear him scream for more.

Her spanking became fingering after a few more minutes, starting with just one finger. Within minutes she was working one whole fist into Frisk's girly ass, then punishing it with two at once, stretching it out while forcing Frisk to apologize for being so greedy.

Frisk apologized submissively, willing to do whatever he wanted to keep her going. He screamed her name when she began using three fists at once, her fourth hands' firm grip on his cock the only thing preventing him from cumming right then and there. From her fingers spread even more purple web, tying his cock to prevent his climax.

"You'll have to earn that girly~" Muffet purred, continuing to abuse his ass for another few moments for shoving him down and spreading her legs, "get to work~" She ordered. Frisk didn't need to be told twice. He buried his tongue into her hot, wet slit immediately, licking in fast circles through her folds to please her as much as possible.

Muffet moaned in delight, tugging on the purple thread connecting the web tying his cock to her hand, let it gher pull his swollen cock to tease him, urging him to lick harder, deeper, and faster. He sucked on her clit hard, trying to push her over the edge.

Muffet grit her teeth, moaning as she came from his efforts, losing her grip on the thread. The purple web vanishing and Frisk cried out, cumming hard all at once, covering the spider girl's legs and feet. Without even being told, Frisk lowered his head and began to lick her clean. Mufet smiled at this.

"Good boy~" She said, "But you're still not done you know~" No sooner had she said this did a little spider scurry up to Muffet with the news that Frisk actually had bought spider food in the RUINS, quite bit of it actually.

She gasped at this, momentarily apologizing and asking if there was anything she could do to repay him. Frisk smiled up at her, "You can keep going~" He purred to her, wanting to have a little more fun with his sexy spider girl before moving on to the next part of the underground. Muffet was confused at first, but smiled as she caught on, just as eager as he.


	10. Chapter 10

Frisk had met up with Sans on his way to the Core, stopping to chat with the revenant about nothing in particular, and have a little semi-exhibitionist fun under the table at MMT resort before Frisk headed through the back exit and into the Core proper, entering the next section of the Core had a completely different feel to it from the rest of the Underground, but then again, Frisk could have said the same thing about every new location he'd been to up to that point.

Still, there was something about the Core that only spurred Frisk onward, instilling him with not only his normal lust, but a sense of energy and determination. He wasn't sure why, and he didn't think too much about it, but the feeling was there, and he let it carry him forward.

His first encounter in the Core was a two on one with the older, more powerful siblings of monsters he'd hooked up with in the RUINS. Final Froggit was much taller and stronger looking than her little sister, with spikes growing from her head and shoulders.

Whimsalot was armored, and seemed to be able to summon a weapon out of thin air with magic. Thankfully, despite their increased power, they were just as vulnerable as their siblings when it came to lust magic, and soon were succumbing to the heat.

If anything, it was easier now, as Whimsalot was less afraid of sex than her sister, and wasn't afraid to get involve with it. They pinned Frisk down, Final Froggit straddled Frisk, dropping herself hard onto his cock and grinding herself against him.

As she moaned, her long tongue extended from her mouth, pushing into Frisk's mouth and even into his throat as she rode him roughly. While she did, Whimsalot let her magical bow and arrow vanish, instead creating a new weapon to dominate Frisk with: a strap on.

It appeared on her body as she approached Frisk, already lubricated when it formed. She thrust into frisk's tiny asshole with no hesitation, grunting with the force of getting it all the way inside. Frisk moaned in delight around Final Froggit's tongue as she gagged him with it, letting the Core monsters have their way with him while he just enjoyed.

When they were done with him, Frisk continued forward, and was next confronted one on one by another core sibling to a RUINS monster, Astigmatism, older brother to Loox it seemed. He was much bigger, and his duel cock much thicker, to the point that Frisk legitimately believed that the species just grew a third leg when they reached a certain age.

Frisk gulped slightly at the sight of it, but his hesitation was nearly non-existent, and he dropped to his knees to take the long of a cock. Astigmatism groaned as Frisk took both heads into his mouth, sucking on both of them as he began to move his head slowly, sucking harder when he reached the point where the two shafts connected.

He gagged slightly when he reached the base of Astigmatism's cock, but didn't stop sucking until he felt the twin-cocked monster's member throbbing hard inside of his throat. Frisk quickly lifted his head, the tips both still in his mouth when the monster came, flooding the human's mouth, and painting his face, with white cream.

It was incredible how much the monster managed to let out; he was practically a one man-bukkakke. And once Frisk had seen that, he of course had to know how it felt inside. Astigmatism was more then happy to oblige.

He turned Frisk around and pinning him on his stomach as he forced his dual-cocks into the bitch boy's tight asshole, stretching it out hard Frisk moaned, the rough thrusting grinding his own stiff member against the cold metal floor, a bizarre level of pleasure coming from the friction against it, and a perhaps embarrassing amount of satisfaction coming when he reached his limit, cumming beneath him.

His clenching ass wasn't quite enough to finish the monster though, and Astigmatism continued to fuck frisk in a small pool of his own cum. Once that was done, Frisk found himself in one more encounter before he reached the end of the Core, another two monster team up against him, though this one was with monsters Frisk had never met.

One was female, an extremely large, even surpassing Greater dog in size. She was built like a tank, or perhaps two tanks tied together, and even when Frisk's lust magic got her to stripe out of her armor, Knight Knight's muscles alone looked like they could have blocked bullets. The other monster was much smaller, only slightly taller than Frisk himself. He looked like a magician, floating in the air with magical orb hands and no arms connecting them.

His name was Madjick, and he was just as quickly affected by the lust as Frisk. Knight Knight grabbed Frisk, pinning him down and lowering herself onto him. She didn't so much force Frisk to eat her out so much as she did use frisk's head and shoulders as a sex toy, as she was just big enough to fit the top part of his body inside of her like a living dildo.

Frisk squirmed as she did this, feeling Madjick making use of the other side of his body, thrusting into his unoccupied ass while his magical orb hands sent painful jolts of energy through his cock. The two of them, kept Frisk for awhile, trading which side they dominated until both of them were too tired to continue, Madjick running out of magical energy and freezing up, Knight Knight falling asleep against the wall.

That was Frisk needed to recover from, catching his breath before he would be ready to continue forward and face the robotic monster he knew would be waiting for him at the end of the Core.


	11. Chapter 11

Frisk wasn't surprised to find that Mettaton had been waiting for him at the end of the Core, having expected a showdown with the mechanical menace at some point. He was however surprised by Mettaton's claim that Alphys had been setting him up this whole time, and worried when it seemed that the tin can was evidently going off script to kill him for real.

Alphys called Frisk again, letting him know there was still a way to survive, a switch on Mettaton's back that would make him vulnerable. when Frisk switched it, the entire battle changed tones. The first thing to happen were cameras jutting from the walls and nearly every angle to watch, and the second was Mettaton's new form, taller, and fully humanoid, with long powerful looking legs and a figure that would drive any women, and many men, who saw it crazy.

Frisk smiled, giving a sexy pose both for the humanoid robot before him and for the cameras, which he could assume were being broadcasting all across the Underground. He didn't mind a little exhibition, and if he was going to be watched, he was going to put on a good show for the viewers at home.

Mettaton seemed to approve of his posing. He was still on the offensive, trying to attack Frisk with his various robotic weapons, but was willing to stop whenever Frisk posed, his cuteness, or his lewdness, always gaining a few extra viewers to the show, which Mettaton could appreciate.

Soon the fight deteriorated, as Frisk's dancing, a combination of gracefulness and sensuality, began subduing Mettaton's aggression. It was a combination of things really, Mettaton recognizing that the dancing was getting more attention than fighting, Mettaton's natural performance instinct, and above all, the fact that in this more vulnerable body, Mettaton was able to be affected by frisk's lust magic.

Soon both of them were dancing, and not long after that, Frisk began to strip down as he danced, losing his shirt and then his skirt, dancing naked for the Underground to watch. Between the dance and the lust magic, Mettaton began to grow too aroused for it to remain hidden, his metallic member growing solid and visible.

Frisk grinned at the sight of it, both because he could tell him plan was working, and because the idea of shy little Alphys taking the time to build a robot cock was slightly amusing. It was always the quiet ones as they said. Frisk began to move his dance closer to Mettaton, until he was pressed against him, rubbing sensually against his body. Mettaton groaned, his metal cock between the femboy's legs.

He tried to hold out, but it was too much. Mettaton reached the same conclusion Frisk had, if he was going to succumb to lust, he may as well make it entertaining as he did so, He lifted Frisk off of his feet, turning the human upside down so he was face to face with Mettaton's long metal member.

Frisk didn't hesitate, opening his mouth and engulfing Mettaton's rod, the robot groaning in pleasure as he buried in tongue In frisk's hole, turning slowly as he did so the cameras could get it from every angle. His member twitched in Frisk's throat at the thought of the entire Underground watching him do this, even his old friends Shyren and Blooky.

It seemed that, as turned on as Frisk was by the idea, being watched was Mettaton's primary kink. Frisk bobbed his head faster, sucking hard as he continued to deep-throat the slick metal pole. Mettaton moaned against frisk's ass, his tongue pushing the tight walls apart in preparation for the fun.

Frisk moaned around Mettaton's shaft, which turned out to be a bit more than he could handle. Mettaton groaned as his cock began throbbing, then shooting thick, warm globs of cum down Frisk's throat.

Frisk wasn't too surprised to find that he could actually cum. Robot or not, he still had monster magic within him, and could still do anything a living organism could. Frisk gulped down the seed skillfully, licking the member clean of them before being set down on the floor, still held upside down as Mettaton moved his legs to either side of Frisk, lining his cock up to the lust soul's hole in such a way that he was able to thrust straight down and penetrate him, both of them moaning out loudly as he did.

Frisk moaned out praise of Mettaton's cock, letting the entire underground know how it felt to be fucked by him. Mettaton was overwhelmed with a mix of embarrassment and intense desire, the latter inevitably winning out as he began hammering Frisk's asshole, his cock lifting and sinking hard into him from above while Frisk remained upside down, taking it all with glee.

Perhaps the blood was running to his head by this point, but it felt too good for him to care, especially when Mettaton's cock made contact with his prostate, the hole clenching even tighter around the metal member, refusing to let it go. Mettaton groaned in pleasure, using more mechanical strength to pull himself out and drive himself back in even harder than before, repeating the process several times to abuse the girly boy's anus.

Frisk cried out, cumming from the third hit against his button. His seed shot over his own face, and he shamelessly licked it from it lips while giving the underground and upside down double peace sign. Mettaton grunted as he felt himself getting close again, his thrusts down into Frisk becoming so rough as to be hydroponically powered.

He pulled on Frisk's legs so their bodies would meet as he bottomed out inside of the femboy, cumming hard with a cry of pleasure, and refusing to pull out until every last drop had been fed to frisk's greedy asshole, which took it all happily. Mettaton panted as he pulled out slowly, his member almost feeling wrong now that it wasn't lodged as deep as it could go inside of Frisk's ass.

Frisk slumped onto his back, then sat up to let the blood return to his body and clear the dizziness that had started to form. He smiled at Mettaton, who was currently laying down, the fun having drained the energy from his new form. Frisk walked over and gave Mettaton a little kiss before he powered down, the path forward now open for him to move on.


	12. Chapter 12

Frisk entered the battle with Asgore, king of the monsters, with a smile on his face. Sans had greeted him in the hallway leading up to Asgore. they'd spoken for a bit, and Frisk realized he wasn't even really sure what he would do when he confronted Asgore.

He'd thought about it as he walked forward, and when he saw the king, all the dots that had been left by Toriel, the history he'd found, and the little snippets Chara had let out here and there, came together. Frisk knew exactly what he wanted to do from that point forward.

Frisk walked towards the boss monster, letting his hips sway sexily as he did so. When he'd been with Toriel, they done a little practice with her fire balls whenever they needed a little rest from sex (which didn't happen often, but still) and so Frisk managed to maneuver his way passed the fireballs and get in close to the tall, bulky monster king.

He smiled up at him, feeling his muscles tense from the look, not from aggression, but from trying to force himself to attack when he didn't want to. He didn't want to fight, and frisk knew it. "Can't we just get to know each other a little better~?" Frisk asked, his hands moving under Asgore's cloak and running along his fur, feeling his muscles.

Asgore tried to take a step back, but Frisk moved with him, pressing himself even closer to Asgore, his face against the goat man's fur as his hands moved lower, "So soft and warm~" he purred, as his hands traced lower, pushing passed the line of his pants.

Asgore hadn't been expecting this, even after what he'd heard from a few of the guards around the Underground. Frisk winked up as Asgore cutely, his fingers tracing over Asgore's currently limp cock, trying to wake it. The lust magic mixed with his sexy form was doing a good job of it, and soon it began to rise.

"S-stop this human." Asgore groaned as Frisk pushed the king's pants down, freeing the massive rod. Frisk was shocked by the size. It was already bigger than any of the others he'd seen, even Greater Dog's, and he wasn't even fully erect yet!

Frisk pouted up at him, "Won't even let me have a final bit of fun before you take my soul?" He asked, moving down to his knees in front of the king, one hand holing the tree trunk of a cock up against this face, the other moving down to gently rub against the goat monster's balls.

"That's very rude you know." Frisk added. "You cannot stall like this forever." Asgore groaned at the fondling, his cock growing even harder. Frisk ignored this, looking up at him as he slowly, teasingly, rubbed his face against the thick shaft of Asgore's cock, "Did you ever think about doing things like this with Asriel or Chara?" He asked

The thought bringing Asgore to full stiffness. Chara had been extremely affectionate in the past, and he'd done more than think, and with how much like Chara this human looked.. it was impossible now for any thoughts to bring his back down or undo the lust Frisk had worked up in him.

Frisk grinned, having known this would work from the pictures he'd found in Chara/Asriel's bedroom, and from the the things Chara had told him when he slept, about all the fun they'd had back before the bad things started happening.

Frisk let his tongue move slowly along the king's giant cock, loving how hard it felt. His soft hand continued to play with his large balls, feeling how pent up they were from going years, YEARS without any release, even from himself.

The thought was utterly nightmarish as far as Frisk was concerned, and even if he couldn't sate the king's need to fulfill his duty, he could remind him of pleasure at the very least. He continued to lick, growing more aggressive with it as he did.

He doubted that he'd be able to take the king's entire length in any hole, but he hoped he'd be able to get him off in spite of it. Frisk moved his head back to the tip of the monster cock, swirling his tongue around it before opening his mouth as wide as he could and moving it down to take as much of the pole into his mouth as he could.

Frisk started gagging at just before the halfway point of the rod, and moved off of it for a moment to please him a different way. He moved his hands up, gripping Asgore's cock with both of them and stroking slow and deliberately as his face moved against his large balls, licking, then kissing, then sucking on them.

He could tell this was working a bit better from Asgore's moaning as he went, and he kept going a bit longer. He knew he wouldn't be able to entire finish him off this way though, and had to move back to try taking his cock again, continuing to fondle him below as he began taking his length inside again.

This time he made it to about the halfway point before he started gagging, but didn't stop, pushing forward and taking another inch before realizing that he couldn't take the rest, which was disappointing considering how much of i there was left. But before he could move his head back, the last of Asgore's resistance broke, and he took action. Frisk felt a strong hand on his head, forcing it down as Asgore thrust forward.

The monster king grunted as he began fucking the girly boy's throat, making it his, raping it as roughly as he could. He knew that he wouldn't be able to take it, or at least shouldn't be capable of doing so, but he didn't care. the combination of lust magic and actual pent up lust was too much, and he cared for nothing in that moment other than release.

Frisk realized as Asgore fucked his face like the slut he was that he couldn't breathe, not at all. He could hold his breath for quite a long time, but it was still a scary prospect when he wondered how long it would take the monster king to cum.

Even when he managed to hilt his cock inside of Frisk's throat, likely breaking at least a few laws of physics in the process, he still wasn't at his limit, Frisk went from simple messaging of his balls to gentle squeezing as he sucked for all he was worth, and this, combined with the fucking, got Asgore off a bit quicker.

He groaned, flooding Frisk's throat, or more accurately his stomach, with a torrent of seed. It was thicker, and there than any monster he'd gotten off thus far, and so much filled him frisk felt he might not need to eat for a week afterwards.

Frisk sputtered for breath afterwards, gasping for air as Asgore tried to recover from the climax. Well, recover wasn't much of an issue really. he was so tightly wound that his member wasn't an ounce softer now than when frisk had woken it, and Frisk had a frightening/exciting idea of what Asgore would want to do with it.

Grinning at the monster king, he decided to cut him a deal, "How about this, instead of taking my soul, you come with me back to a certain goat mommy I found living in the RUINS? We can stay there like a family, and you can both use me as your little slut whenever you want~" Frisk moved over, slightly difficult with the sloshing feeling of cum in his stomach, and rubbed Asgore's still throbbing cock affectionately.

Asgore smiled at the offer, "Human.. that sounds wonderful..' Frisk smiled, happy to know he could spend the rest of his life with these monsters... a happiness that was cut short when vines sprouted from the ground, sticking through Asgore in every angle they could, reducing the king to dust.

Even his soul was broken by the attack. Frisk was too shocked to move as Flowey rose from the ground, a grin on his face as he thanked frisk, saying he'd have never been able to steal the souls without Frisk's help. Frisk watched in horror as Flowey brought the six other human souls towards him, absorbing them all at once.


	13. Chapter 13

Frisk stood his ground when Flowey appeared, his body now a massive tangle of planet and meaty matter. He wasn't sure where exactly they were other than just a dark empty void of a room, but he know he could handle whatever the monster did to him, no matter how intense it got. Hell, maybe he'd even enjoy it.

Flowey seemed determined to prove otherwise though. The moment the battle began, massive vines shot at him from all directions, lifting him from the floor and holding him with his limbs all pulled in different directions, leaving his body entirely open.

A blast of white projectiles cut his clothing entirely off, leaving him naked and at the monster's mercy. Frisk remembered thinking Asgore's cock was the largest thing he'd even even thought about taking. He nearly laughed at that thought when Flowey's vines, which somehow seemed to be even larger than Frisk's body, though that may have just been his fright in the moment talking, began forcing their way into his mouth and ass at the same time.

He remembered feeling as though his jaw would break and his body split in two just from taking the two vines, the pain only growing as two more vines joined in, both trying to worm in next to the vines already fucking him. Another set of vines slapped painfully against his balls, tugging on his cock as though meaning to remove it.

The pain was immense, but frisk focused on his lust magic, and was able to find the pleasure in it, mockingly moaning around Flowey's vines as he took them. Flowey hissed angrily at this, rising more vines and burying them even harder inside of frisk's body, stretching him apart like an overused rag doll.

Frisk was glad there were no reflective surfaces in the area, because seeing the contortions his body was likely going through as Flowey somehow, likely magically, managed to stuff six vines into both holes without killing him-though with the reset ability Chara had warned out, it's possible he actually had killed him and just re-done it to make the pain last longer.

Frisk remembered wondering if it would ever end, and then just as he'd thought it, a strange warning sign appeared, flashing a bright blue. Suddenly the area somehow became even darker, the vines vanishing as a bright blue ball-gag appeared, stuffing itself into Frisk's mouth to silence him as unseen hands groped his body.

It was strange, but somehow easier to deal with as he moved his body in rhythm with the body of of whatever was toying with him. He heard a barely audible cry of the pleasure, as though someone where cumming, and the ball gag vanished. The warning light flashed again, this time orange, and several bright orange paddles appeared floating around Frisk. They moved forward, striking his body all over, but of course focusing on his ass and cock.

As they punished him, Frisk once again felt that invisible presence, this time though he very clearly felt a member as it took his mouth. As it was of normal, non-monstrous proportions, it was easy to handle, and when the phantom once again came, the paddles vanished and the warning light appeared again, this time a dark blue.

The paddles became replaced with dark blue stocking covered feet. frisk was kicked to the ground, and trampled by the feet. The ground their heels and toes against his body, face, crotch, and even pushed into his ass to stretch it. And once again, there was that presence.

Frisk began to think that they were not the same presence though, different beings with different powers. This time he felt feet against his face, but not the massive weapon stockings, and as he felt it, he felt a wet slit around his rod.

As before, frisk followed the motions of the presence, thrusting against the evidently female phantom as he kissed and licked a the feet he couldn't see. When she came, the warning light flashed again, this time a purple color.

The stockings became a pair of purple handcuffs, locking his arms above his head and his feet apart. He grunted as he felt a member penetrate him roughly, though after Flowey's vines it was nothing. It was much too big to be a futa though, making Frisk certain that this was many beings, not just one with an alt. gender.

When the member reached its limit inside of Frisk's girly asshole, the warning light flashed green, and the shackles vanished, replaced with a single, massive dildo. It looked more like a strap-on really, but no one was wearing it, and considering it was big even to Frisk, the reason why no one was using it was clear.

The femboy got onto his fours, figuring that would be his best chance of taking the over-sided surfboard of a strap-on. he grunted, and as it fucked it, he felt a pussy grinding against his face, the presence accompanying this attack. frisk let her/he use his face, submissively taking it, striking to what he knew best.

Thankfully this once came faster than all the others and the strap-on vanished with it, the warning light flashing yellow, confirming Frisk's belief that they corresponded to the six human souls Flowey had absorbed. A yellow rose whip appeared, long, sleek, and covered in sharp looking studs. Frisk gulped, but didn't back down, letting the whip last at his body, marking and cutting it in every way it possibly could.

He wince when he felt the cuts forming across his chest and ass, when he felt the sting of the whip against his tiny cock. Even for a masochist this was a bit much to handle, but Frisk didn't back down. As before, he could also felt a presence there groping it, biting his neck as it penetrated his ass. This one lasted longer than all of the other rounds put together, the lashing and fucking very nearly finishing Frisk off, but his lustful soul let him continue on, enjoying the sensation just enough not to give in.

When the phantom came and the whip vanished, Frisk saw them, the six souls, each with a different form of magic. He could sense them within Flowey, and could sense that they were trying to help. In a flash, all the damage and punishment his body had taken was undone, and he felt better than when he'd started the fight, maybe better than he had in the entire underground.

Flowey re-appeared, evidently ignorant of what had happened with the souls, and of them actively weakening him from the inside. He buried his vines back inside of frisk, but now the pain wasn't overwhelming. It still hurt, but now it hurt just enough for frisk be moaning like a bitch around Flowey's vines, begging for more.

He wasn't sure if his body had been made stronger for Flowey's weaker, but suddenly the vines fucking was incredible, he clenched hard around Flowey's vines, and after a long time of Flowey trying and failing to break the femboy, it was Flowey who reached his limit, his vines expelling a massive flood of thick, gooey seed into frisk from both ends, filling him so much he looked several months pregnant.

As Flowey panted, the souls made their move, bursting from his body in every way they could, forcing their way out. In a flash of magic, Flowey was just a Flower again, sitting on the floor. Frisk had a powerful instinct to run up and punt the flower out of the dirt, but he didn't.

He refused to stoop down to the flower's level. He walked over, and gave the flower a gently, affectionate peck of a kiss. Flowey seemed confused, outright shocked by this, and in a fit of anger, declared he would rest to before this had happened. "Maybe this time you'll have made better friends with Alphys." he mentioned.

Thanks to Chara's presence, he still remembered Flowey saying this when the reset happened, still remembered everything in fact. He was standing right outside Asgore's door. He turned back, wondering what Flowey had meant, and knowing the only way to find out would be to go talk to Alphys.


	14. Chapter 14

Frisk had known about Undyne's crush on Alphys for a bit, and had known about Alphys' mutual crush on Undyne for as long as she'd known her. His initial plan had been not to interfere so it happened naturally, but now that he'd been sent back in time, and could see quite clearly that the two of them were in need of assistance, he decided to lend a helping hand. It started with delivering Undyne's love letter to Alphys, as she couldn't do it herself.

Alphys mistakenly believed the letter to be from Frisk though, and wound up, rather indignantly, on a pity date with Alphys. Frisk realized he could put this to his advantage though, clearing out a section of Waterfall for the 'date', which the location of which he let slip to Undyne.

When Undyne showed up, Frisk bolted out of the area, or at least to where the two monster girls could no longer see him and assumed they were alone. Awkward standing around became talking, then confessing, then accepting, and finally, kissing.

Frisk grinned as he watched the two monster girls kiss. It was slow and gentle at first, both of them slightly nervous about it. Soon Undyne's natural aggressiveness kicked in though, and she picked up the pace, her hands trailing over Alphys' body, pulling her closer as she deepened the kiss, tongue pushing into her mouth. Alphys shuddered, still nervous, but too excited to resist Undyne's advances.

Undyne's hands traced down her back, finding and groping her round ass. Alphys moaned into the kiss. They kept going, Frisk getting a little worked up as they continued, both slowly stripping out of their clothing.

Frisk realized after the fact that his presence, his lust magic was probably what was jump starting their relationship, forcing their date directly to the lustful stage; not that either of them had needed much pushing in that direction.

As the monster girls continued, they paused, having heard frisk's gentle moaning as he watched them. Frisk froze when he realized he'd been heard, wondering if he could run before Undyne started throwing spears again, or if he was already stuck.

Thankfully, Undyne didn't respond with hostility, grinning as she beckoned Frisk over to her and Alphys. Frisk grinned, his excitement only intensifying the lust magic and he walked over to the new couple. Alphys was visibly nervous about Frisk joining them, but between the lust and the excitement in general, she decided to just go for it, much to Undyne and Frisk's delight.

Undyne pulled Alphys back into another kiss, then lowered it across the drake girl's neck, then down across her chest and towards her crotch. Alphys moaned softly, already growing wet just from the thought of Undyne's tongue against her pussy, let alone the actual feeling of it. She squeezed in surprise when she felt a second tongue though, Frisk's teasing between her cheeks and licking around the outside of her other hole.

Her body was tense, but it wanted it too much for her to stop them as Undyne and Frisk's tongue both entered her on either sides, both licking rapidly inside of her. Alphys moaned loud enough to alert any monsters in the entire area, though Frisk had already cleared the place pout for specifically that reason.

The yellow drake girl's hips moved reflexively for more, bucking back and forth against both of their faces. Undyne's hand moved up to toy with Alphys' clit as Frisk moved his hands to grope her round rump, the combined effort of them playing with her body pushing Alphys over the edge quickly. Alphys groaned as her juices washed over Undyne's face.

She licked her lips, the Alphys' so she could taste her own juices. Alphys blushed deeply at this, but it didn't stop her from licking her lips to taste it. Undyne grinned, moving Alphys onto her back as Frisk got behind them. The fish girl lined up her member, harder now than Frisk had ever seen it, to Alphys' eager, wet pussy.

Both of them moaned in pleasure as Undyne began pushing into Alphys, Frisk moving his head down to lick at Undyne's. The movement of her hips started slow, but eating the royal guard girl got more difficult the more aggressive Undyne's thrusts into Alphys got. Frisk didn't mind, enjoying the challenge.

He held onto her hips, tongue working diligently in her pussy while his fingers pumped into her other hole, four fingers working inside her ass and trying to match the pace she was thrusting into Alphys. With how eager the both of them were for this, neither of them lasted long despite Undyne's proven endurance.

Alphys reached it first, screaming out Undyne's name as her pussy clamped around her rod, squeezing it hard as her juices poured over it. Undyne grunted, continuing to hammer into Alphys for another full minute before she went over as well, moaning Alphys' name as she came, pumping warm seed deep into her.

Both of them panted, but Frisk's magic prevented them from being worn out too had enough in them for one more round, and now that Alphys had loosened up enough for the magic to get her to be aggressive, both of them wanted Frisk as well.

They pulled the femboy between him, Alphys forcing his head between her legs, locking them around him so he couldn't move away. Frisk's face was ground against the wet slit of Alphys' pussy for a few moments from her movement before he managed to push his tongue inside and begin eating her properly, his tongue vibrating with moans as Undyne's spear found its next target, penetrating Frisk's ass roughly and fucking him against her new girlfriend.

Frisk suspected it would be quite awhile before any of the three of them left Waterfall. He wasn't sure how exactly this would change the timeline, or even if it would at all, but he was already thankful for the reset Flowey had allowed.


	15. Chapter 15

Frisk was confused and afraid when he found himself in the True Lab below Alphys. He wasn't sure what he would find, nor what he would do when he found it. He was glad at least to know that something had changed in the timeline, and according to Chara, he was on the fast track to another ending, a better ending, if he could just survive whatever he found.

The first of the strange beings Chara informed Frisk were called Amalgamates that he saw were the Memory Heads. They vanished from view, teleporting in various locations around Frisk. Standing in the wrong place meant being telefragged by their appearance.

Frisk managed to calm them, or perhaps calm isn't the right word, with his lust magic, sending out a pulse when all three of them were present. All three of them were affected, teleporting around Frisk and latching onto him. Frisk couldn't fully describe what it was they did to him exactly, but he supposed it was fucking.

He felt himself get penetrated by one of them, though considering the melted masses of them, it could have been any one of them and he wouldn't have known, or even all three at once. Two of them latched onto his chest, biting and sucking aggressively on his nipples.

Frisk moaned, letting himself enjoy the pleasure, odd though its source was. When the Memory heads came, Frisk didn't feel himself get filled with anything, and as quickly as they'd appeared, they vanished, leaving Frisk alone and very confused.

The second Amalgamate was called Reaper Bird, or at least that's what Chara daned to call it. frisk could gradually make out the individual monsters it was a combination of, sand though the thought of how they'd come together was confusing, frisk managed to lure it in with lust magic just the same.

Reaper Bird pinned Frisk beneath it with it's long legs, a large, triple headed member penetrating Frisk's hole from behind. As it didn't, the amalgamate stretched itself over, and a wet slit covered Frisk's face. Frisk refused to look at the mirrors in the hallway, not wanting to know what bizarre angles the creature was at to achieve such a position. He simply bucked his hips to take the creature's rods deeper and licked for all he was worth, getting the creature off quickly.

He could recognize the moans of the different monsters, Froggit, Whimsalot, Astigmatism, and it was directly on the borderline of sexy and creepy the way the three sets of pleasured groans overlapped as Reaper Bird came, dumping seed from all three tips and drenching Frisk's face before slinking off into the shadows.

The third Amalgamate frisk encountered was called Lemon Bread by Frisk, though for what reason Frisk didn't know and Chara didn't say. Frisk tried to move peacefully over to it, his lust magic radiating out.

Thankfully, by the time he was close enough to the creature, his magic had replaced any confusion and anger within the amalgamate with raw lust, and Frisk was pinned down for fucking, not killing. He shuddered as strong, Aaron like arms wrapped around him, holding him in place as a gooey yet solid rod pushed into him, hammering away at his hole.

The moaning of the creature was, as with Reaper Bird, many different moans overlapping, though it was somehow more melodic with Lemon Bread, more in sync. Frisk wasn't sure if that made it less frightening or more so, and decided to just let it be, remaining with Lemon Bred until it reached its peak, and then, pacified, left the area clear for Frisk.

The fourth Amalgamate Frisk found was just.. just sad. He could recognize the monsters composing it, a Vegetoid, a Snowdrake, and an Icecap, but he knew full well who the Snowdrake was; the missing mother that he'd heard about before.

Frisk dutifully went to work sating this one as all the others, but she didn't seem to have the energy to even pounce on him, just slowly crawling onto him and lowering her chillingly cold slit onto his member, grinding against it as ice cold, snow white vines snaked down from her form and pushed into his ass.

Frisk shuddered, ramping up the lust magic to try and make it as fun for her as he could. Somehow, even when she was satisfied, frisk felt that it wasn't enough.

Thankfully the last Amalgamate Frisk met was much easier to have fun with, and to comprehend; it was massive canine, composed entirely of other canines. The lust magic worked better on it than it had on any of the others, and it followed it's instincts to root Frisk.

Frisk yelped when he felt the Endogeny's member push into him. it was bigger than Greater's, just barely smaller than Asgore's. That by itself was more than easy enough to take, but Frisk couldn't even imagine what would happen when the dog beast tried to make Frisk take the knot.

Somehow Frisk managed not to black out from it, and when the amalgamate left him, he was able to continue exploring the True Lab. He found old tapes from the Dreamurr castle, though it didn't contain any information that Frisk hadn't heard from Chara already.

He continued through, eventually reaching the power room, where all of the amalgamates clustered around him at once. With their expressions being what they were, it was difficult to tell if they planned to all gang up on him for hotter sex, or to get the murder they;'d not managed to get previously.

Either way, they all scattered when Alphys let them know they had food waiting for them,. Alphys explained what she'd done with her experiments, and was planning on finally sharing the information with the rest of the underground. Frisk was proud of her, slightly less proud when he learned that her experiments may have also created Flowey, but he knew it wasn't her fault.

When he was on his way out though, one of the elevators began moving him upwards with him turning it on, and he was brought directly to Asgore's castle. It seemed his new ending wanted to happen now.


	16. Chapter 16

Frisk held his ground against Asriel. Powerful as the monster was, Frisk knew he didn't really want to hurt anyone, or so he'd been told by Chara, who he trusted too much to doubt now. Frisk may have been royally pissed at him for stealing the souls of his friends, and reeling from the shock of his origins as the evil flower, but he wasn't going to let that slow him down.

He pushed forward, dodging the hyper-god's overpowered, otherworldly attacks and getting in close, just as he had with the prince's father in the previous timeline. He held onto Asriel, hugging him close as his lust magic filled the.. wherever the fuck they even were anymore, it was hard to say with all the magical color swirling around them.

Asriel groaned softly as the magic, combined with Frisk's soft body against his, waking his member. Asriel seemed to believe fully that frisk was actually Chara, and Frisk decided to use that belief to his advantage.

He kissed the goat boy's neck, "come on brother~" He whispered to Asriel, "I thought you said you wanted to play with me~ why don't we have some real fun~?" he asked, adding at Chara's request the phrase, "Just like we used to~"

Asriel, in his current state, could likely have handled a nuclear blast without flinching. he could not remotely handle that. A blast of magic burned the clothing clean off of his body, and before Frisk knew it he was bent over on his knees, member being stuffed into him from behind.

Frisk cried out in bliss, "S-so fucking big~" It was true, the soul fused monster's rod was even bigger than Asgore's had been.

Not so big that the mere size alone made it painful like Flowey's vines, but big enough to make Frisk shriek just from having it inside, cumming after just a few moments of him thrusting inside. Asriel laughed at this, smacking frisk's ass so hard it left a burn on his girly butt-cheek.

He pulled Frisk's arms back by his wrists as he thrust in harder, trying to hilt himself inside who he believed to be his sibling. "So, fucking, tight~" He moaned, "if I'd known it would feel this good Chara, I'd have never waited back then~" Frisk could make the assumption that even when Asriel and Chara had been doing things together, it had been Chara doing the topping. for once, frisk wondered if Chara could actually feel what he was feeling.

In a weird way, he kind of hoped that they could right now. Frisk came a second time when Asriel's cock got balls deep inside of him, then a third moments later. With the energy of every soul, monster or human, in the underground, Asriel could likely keep going forever.

And with the way Frisk's soul turned lust and sex into more energy for more lust and sex, the two of them seemed to be in a stalemate, Asriel eventually reached his own climax, groaning in delight as his balls tightened before releasing into frisk, pumping him full several times over.

Frisk slumped to the ground, panting as he looked over his bloated, cum filled belly. Asriel just laughed as he thrust back into him, "Don't think you''re doing any good just because I got off once," Asriel said, "I'm barely using any of my real power right now, if I went all out, i'd fucking destroy you~"

Frisk was almost certain Asriel was right, but knowing he'd never be able to beat Asriel like this, he challenged him, "really? Phew, for a second I was worried this baby cock was the best you had~" He taunted, giving the goat man a wink, "Come on Azzy, show me what you've really got~"

Asriel snorted, "Might as well let you see the real thing before I sent this whole timeline back to the beginning."In a flash of magical energy, Asriel's body expanded, taking on his true form. It was massive, his body towering over Frisk at a size perhaps even bigger than Omega Flowey had been.

He was able to pick frisk up in one hand and completely cover him with his fingers. Frisk's eyes widened in fear when he saw Asriel's cock, which looked bigger than Frisk's entire body. Asriel held frisk against his body, facing away from him as he thrust up, the femboy's soul cracking just from the tip of it penetrating him.

Frisk cried out in pain too intense for the pleasure to counter as Asriel worked more of his cock inside. Frisk closed his eyes, waiting for his soul to rip apart.. but it didn't... it refused... frisk's eyes opened, and he could see the cracks in his soul filling with a different shade of red: determination.

Chara was lending their own determination to keep Frisk going. The combination of lust and determination reinvigorated Frisk with an amount of energy he felt might make him explode. His pained screams became pleasured again as his body adjusted, able now to deal with the power Asriel was displaying.

Asriel grunted as he worked more of his rod into frisk, "H-how are you not breaking?" he questioned, thrusting ind deeper, causing Frisk's stomach to bulge out above his own head. Frisk just moaned, wrapping his arms around the bulge to stroke it while it was inside of him. Asriel growled in a mix of pleasure and anger as he picked up there pace, giving it all he had, but unable to match the combination of Frisk and Chara.

It got to the point where Asriel was not so much fucking Frisk as wearing him on his cock like a sleeve, shouting at him to give up and let him win already, that way they could reset and never have to be apart for good, but Frisk didn't give in, and the pleasure eventually became more than Asriel could handle. He groaned as he came, painting Frisk from head to toe, inside and out, covering every possible inch multiple times in thick white seed.

If Frisk were female, he was sure he'd have been knocked up with quintuplets from the thickness of it, and when he looked around, he saw Asriel, no longer the gigantic beast, but the brother that Chara remembered, sitting down, gasping for breath.

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 **Warning: ne** **xt chapter is the finale.**


	17. Chapter 17

**Already, let's close this with a bang shall we?**

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Frisk wasn't quite ready to leave just yet. All of his lovers had been rescued, yes, even including Asriel. It had taken a lot of effort and magic from everyone involved, but his body was stable now, as was his new soul. His soul was still closer to that of a human's than a monster's, but if anything that would just ensure that he would be staying around for a long time even if things did go wrong later.

But Frisk wasn't ready yet. There was still one order of business he needed to attend to. In fact, seeing Asriel's new soul had been what let him realize that he still had a little unfinished business left in the Underground that needed to be resolved before they could continue on to the surface and start their new lives. He promised everyone that he'd be back as quickly as possible, and bolted through New Home, through the Core, passed MTT Resort, through Hotland, and into Alphys' lab. He went down the elevator to the hidden True Lab beneath it.

The Amalgamates had been released to return to their families, so they weren't the ones Frisk was there to see. After Asriel had used everyone's magic to break the Barrier, all their souls had returned to where their bodies would have been before it had happened. And if that was true, and he'd been using the six human souls as well, then that would mean the six of them would re-appear as well.

He smiled when he reached the True Lab, finding that the room with all the beds was now empty of fused monsters, but full of humans. Frisk had to do a double take of it though, as he was counting seven there, not six. His eyes widened at the realization. He'd not thought about it, but he hadn't heard Chara's voice in his head since the battle with Asriel.

Chara stood among the other six humans, just as alive as the rest of them. All of them were naked, making it easy to tell what gender they were. Patience and Justice were respectively a normal female and male. Integrity was a futa, with Courage being the male equivalent to a futa, a shemale. Perseverance was a D-girl, Kindness her opposite as a C-boy. And Chara stood in the center of them, a herm.

Frisk really had just been intending to find them and bring them all up to the surface with the others, perhaps have a little fun with them all later when they were adjusted to their new situation, but he couldn't help himself. The moment he saw the naked humans, Chara in particular, a burst of lust magic left him as he became immediately aroused, forcing the seven humans into a similar state. Now that everyone was in need of release, it would have been cruel to just leave them like that without helping them.

Explaining that it had been his fault, Frisk graciously offered to relieve their desires, all of them accepting instantly; even Chara, who didn't actually seem to have been affected by the lust magic due to all the time they'd spend inside of Frisk's lust soul to begin with. They weren't afflicted with the artificial lust, they simply wanted Frisk, and had for quite a while now.

Frisk had all the humans stand side by side so he could pleasure them going down the line however they chose. He started with Patience, who asked him to get onto his fours. Frisk gave her a giggle girlier than her own and got onto his fours. Patience moved down, hiking Frisk's skirt up and groping his sexy bubble butt gently, spreading his cheeks before pushing her tongue between him and beginning to lick inside his asshole. Gentle and nice a human as the girl appeared, Frisk's lust magic had brought out her dominant side; as it tended to do.

Frisk moaned as he felt her tongue push inside his tight hole, surprised by how deep it got as she teased his tiny hard on with the tips of her fingers. When her tongue moved out of her, she rubbed the tip of a strap-on against it. Frisk genuinely at no idea where she'd gotten the toy, and could only assume that either Alphys had had one laying around in the room, or Patience was able to form them with magic.

Either way, Frisk was left moaning as she jerked her hips, forcing the shaft into the lust soul's somehow still tight ass. She gripped his hips, pulling them back as she thrust her hips to push the toy deeper inside. Frisk moaned louder as she kept going, getting more and more into it as she went. Frisk could feel the other humans getting more aroused as they watched it, their gratitude for being revived the only thing stopping them from ganging up on him all at once; not that Frisk would have minded them doing so.

Patience brought her hand down hard on Frisk's ass as she continued to hammer her toy into it, biting her lip as she kept going, moving Frisk's body back and forth on the floor as she got closer from the pegging. Frisk felt himself clench around the toy as it hit deep inside of his girly ass, but Patience still came first, groaning softly in pleasure as she reached her peak, juices dripping along the length of the toy.

She pulled out before Frisk could cum to, the denial another show of dominance from her. Frisk whimpered for a moment, but didn't object to it. He turned to the next human in the line, Courage, and moved over to him. Frisk moved onto his knees in front of the shemale, gripping his member and beginning to stroke it as he moved his head between Courage's legs to lick at his cute little pussy.

Tough as Courage was trying to act, it was hard for him to contain the cute little moans he let out as Frisk began pleasuring him, skilled hand pumping along his length and skilled tongue working fast inside of his pussy. The former began leaking precum quickly, the latter getting wetter every second as Courage was moved closer and closer to his orgasm; his first in generations come to think of it.

Frisk felt Courage warm cum shoot over his hair while his juices drenched the femboy's face. He grinned sexily up at Courage, licking his lips giving the shemale a wink before moving over to the next human in the line; Integrity. The futa was blushing in spite of her desires being clear from the lust magic, member stiff and on full view as her eyes didn't leave Frisk's feminine feet.

Grinning as he realized what Integrity wanted, Frisk leaned back and lifted his feet up gently, letting his toes brush back and forth along her cock teasingly before moving them up more and squeezing her cock between his feet. Integrity groaned as she felt him stroke her, feet pumping from the tip of her cock down to the base and back again. He wasn't an expert with his feet, though in retrospect he'd probably start practicing more, but he had Integrity moaning in bliss as her cock leaked precum onto his feet.

When he felt that she was getting closer, he moved one foot lower, rubbing it at her wet slit as the other foot continued to grind against the dark blue soul's cock. Integrity bucked her hips in pleasure, member pressing harder against his left foot as the movement pushed the toes on his right foot inside of her pussy. This pushed her over the edge, Frisk's feet getting two different kinds of cum to cover them.

As she panted, Frisk moved himself to the next human in line. Perseverance, despite her obviously more bookish nature, seemed to be slightly more riled up than the rest, her glasses fogged over as her cock throbbed in need, leaking before Frisk even managed to touch it. He kissed along it affectionately before moving his head underneath her, taking her large, needy balls into his mouth and sucking hard on them as both of his soft hands gripped her cock, stroking it together as he sucked.

Perseverance moaned out gratefully at the feeling, balls pulsing in Frisk's mouth as he sucked and hips thrusting slightly to push her cock faster between his hands. She was the second largest cock in the room behind Chara, and it seemed aching to cum. Frisk let his tongue move lovingly along her swelling balls as he jerked her rod faster to get her over the edge.

When she did reach her limit, her seed poured over his hair, mixing with Courage's. Frisk giggled at the cute look on Perseverance's face as she panted, and moved on to the next human. Kindness was the only human present with any reluctance left after the lust magic circulating through the area, but still gave in to his desires after just a little prodding from Frisk.

The C-boy pinned the lust soul beneath him, taking a seat on his face. Frisk held onto his hips as he pushed his tongue inside of him, stirring his cunt slowly at first, but picking up the pace as he went, loving the sound of the C-boy's moans as he began to move his hips to ride Frisk's face more aggressively, his juices delightfully sweet tasting as he got closer.

Kindness only lasted a short while before he reached his peak and soaked Frisk's face in his sweet juices, panting hard as he pulled himself off of Frisk to rest, laying back as Frisk moved over to pleasure the next human, Justice. Frisk decided to go with something simpler for him, just turning and rubbing his soft, smooth ass against the cowboy's stiffened cock.

Justice groaned as Frisk began grinding against him, his rod pushing between the lust soul's asscheeks, essentially being stroked by them as Frisk moved his hips against him, loving the hard, throbbing feeling against his ass, already imagining it plowing him endlessly like it no doubt would be soon. Justice started moving his hips as well, grinding himself against Frisk more actively.

Frisk moved his hips forward when he felt Justice reaching his limit, that way the yellow soul would paint Frisk's ass white with his release instead of shooting into his own face from the angle they were in. Grinning at the feeling, Frisk turned to the last human present: Chara. They were practically shaking with the need to fuck Frisk senseless, but Frisk decided to start slowly with them. Well, slow relatively speaking at least.

He lowered to his knees in front of her, leaning forward and wrapping his lips around the herm's long, stiff cock. Chara moaned Frisk's name softly as his head began bobbing along their cock. After a few moments of this, he moved his hands between their legs, one gently fondling and massaging the herm's balls while the other gently trailed along their pussy before pushing inside with his fingers. Chara's moans grew louder as so many of their pleasure points were given attention at once.

Chara moved their own hands to their chest, shamelessly groping their breasts, fingers pinching and tugging their nipples aggressively. The only part of their body not being pleasured was Chara's ass, and the determination soul was far too dominant for that. Chara's body shook with delight from the pleasure they received from their submissive little femboy, being brought to the edge by the mental picture of their cock buried to the hilt inside of Frisk's bitch boy ass.

Frisk, having taken Chara down to the base, gulped down their seed effortlessly, looking seductively up at them as he pulled off slowly, a trail of saliva connecting his mouth to Chara's cock for a few seconds before breaking as Frisk stood. "Alright," Frisk said teasingly, "Everyone's cum, so we're done here." He turned around and started towards the door.

Frisk knew full well there wasn't a chance he would be leaving the true lab or even this room for another few hours. He wouldn't be leaving until he was so stuffed with cum and drenched in juices that he resembled a well made turkey. His lust magic had the humans far, far too riled up to stop now or any time soon. He just wanted to make them take him by force; it was always more fun that way~

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 **And that's a wrap for this story!**

 **So what did you think? Not just of this chapter, but of the story as a whole. If I'm honest, there's a few chapters that I feel I sped through too quickly, but I'm actually rather proud of a few, the Asgore chapter in particular. That said, what was your favorite or least favorite chapter of this story? Why do you think it was good/bad? Let me know, as well as what kind of femboy or undertale story you'd like to see next, in the reviews.**

 **I'm sinful by nature with no malicious intent, and I'll see you all next time!**


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